@charset "UTF-8";
body {
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: black;
}

img {
  width: 250px;
  height: 250px;
}

.container {
  position: relative;
  margin: 0 auto;
  width: 1000px;
  height: 850px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  flex-shrink: 1;
}
.container .pointer {
  --x: 0px; /* 图片左上角的横坐标，动态*/
  --y: 0px; /* 图片左上角的纵坐标，动态*/
  --s: 250px; /* 图片的尺寸，动态*/
  position: absolute;
  box-sizing: border-box;
  width: calc(var(--s) + 40px);
  height: calc(var(--s) + 40px);
  border: 3px solid #fff;
  top: calc(var(--y) - 20px);
  left: calc(var(--x) - 20px);
  transition: all 0.3s ease;
  cursor: pointer;
  -webkit-mask: conic-gradient(at 30px 30px, transparent 75%, #fff 75%) 0 0/calc(100% - 30px) calc(100% - 30px) repeat;
          mask: conic-gradient(at 30px 30px, transparent 75%, #fff 75%) 0 0/calc(100% - 30px) calc(100% - 30px) repeat;
}